-
-
Save eregon/234ebf02c3d723913355 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# Benoit Daloze | |
# Ruby Programming Challenge For Newbies #4 | |
# pretty-print polynomials | |
# | |
# My solution use Enumerable#inject to build the String, | |
# with every "monomial" splitted in 3 parts : sign, coefficient and variable | |
class Polynomial | |
def initialize(coef) | |
raise ArgumentError, "Need at least 2 coefficients" if coef.size < 2 | |
@coef = coef | |
end | |
def to_s | |
return '0' if @coef.all? { |c| c == 0 } | |
(0...@coef.length).inject("") { |s, i| | |
coef, pow = @coef[i], @coef.length-1-i | |
if coef == 0 | |
s | |
else | |
s + | |
(coef > 0 ? '+' : '-') + # sign | |
(coef.abs == 1 && pow != 0 ? '' : coef.abs.to_s) + # coef | |
(pow < 2 ? 'x'*pow : "x^#{pow}") # var | |
end | |
}.sub(/^\+/, "") | |
end | |
end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment